Some utilities for comparison notebooks

cc @Peter9192 and @sverhoeven:
More path to ewatercycle system-related config file (grouped based on models):
- comparison_base_dir
- forcing_base_dir
- shape_dir
- aux_dir
- model_output_base_dir
- analysis_base_dir

Example usage would be:
`MODEL_OUTPUT_BASE_DIR = ewatercycle.config.CFG["model_output_base_dir"]["marrmot-m01"]`

Generic util functions that can be used by most of the models:
- get_work_dir(absolute, relative, model_name) e.g. `ewatercycle.config.CFG["output_dir"] / model_name_{time.strftime('%Y%m%d_%H%M%S')}"`
- get_catchment_area(shapefile)
- generate_file_names(some_info)
- save_model_output(model_output, file_name) either time series at one location or spatial data at one time
- open_data_as_dataframe(file_name) e.g. get_precip_from_forcing(file_name) or get_simulated_streamflow(file_name)
- join_data_to_dataframe([simulated, observations, precipe])

Marrmot calibration module that can be used for three marrmot models:
- objective functions e.g. objective_function()
- running functions e.g. run_calibration()
- saving functions e.g. save_parameters() now it is based on yml but it can be csv.
- plotting functions e.g. plot_calibration()

lisflood specific that can be added to forcing module:
- generate_convex_hull_shapefiles(shape_file, model_mask)
- merge_forcing_files
- lisvap

I didn't look at hype, pcrglob and wflow.